/*

* Copyright (c) 2010 Nokia Corporation and/or its subsidiary(-ies).

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description:  Cache for authentication credentials

*

*/

#ifndef CREDENTIALCACHE_H

#define CREDENTIALCACHE_H

#include <e32base.h>

#include <vpnapidefs.h>

class MIkeDebug;

const TInt KCredentialMaxLen = 64;

/**

 * Cache buffer stored to file.

 */

struct TCacheBuffer{

  TVpnPolicyId             iId;

  TBuf8<KCredentialMaxLen> iUser;

  TBuf8<KCredentialMaxLen> iSecret;

};

/**

 * Cache for authentication credentials.

 * The public interface of the class has been

 * designed for CTransNegotiation use.

 *

 * Error handling:

 * The methods return error code or leave only if

 * it is useful for the method caller to handle the error.

 * The user of CCredentialCache must work even if the

 * cache fails. (The credentials are asked from user in that case.)

 *

 * Example usage sequence:

 *   NewL

 *   SetUserName

 *   SetSecret

 *   Store

 *   GetCredentials

 */

NONSHARABLE_CLASS( CCredentialCache ) : public CBase{

  public:

    /**

     * Two-phased constructor.

     * @param aDebug Debug log interface.

     */

    static CCredentialCache* NewL( MIkeDebug& aDebug );

    ~CCredentialCache();

    /**

     * Sets user-name. Does not store to file.

     * @param aUser User name.

     */

    void SetUserName( const TDesC8& aUser );

    /**

     * Sets secret, e.g. password. Does not store to file.

     * @param aSecret Secret, e.g. password.

     */

    void SetSecret( const TDesC8& aSecret );

    /**

     * Gets credentials from cache file.

     * Caller is responsible for deallocating aUser and aSecret.

     *

     * @param aVpnApId VPN access point id

     * @param aUser On return, user name.

     * @param aSecret On return, secret.

     *

     * @return KErrNone if credentials are fetched from cache.

     * @return System-wide error code if cached credentials are not available.

     */

    TInt GetCredentials(

        const TUint32 aVpnApId, HBufC8*& aUser, HBufC8*& aSecret

    );

    /**

     * Stores user-name and secret to private file.

     * @param aVpnApId VPN access point id.

     */

    void Store( const TUint32 aVpnApId );

    /**

     * Clears cache.

     */

    void Clear();

  private:

    CCredentialCache( MIkeDebug& aDebug );

    void ConstructL();

    /**

     * Gets credentials from cache file.

     */

    TInt GetCredentialsL(

        const TUint32 aVpnApId, HBufC8*& aUser, HBufC8*& aSecret

    );

    /**

     * Stores user-name and secret to private file.

     */

    void StoreL( const TUint32 aVpnApId );

    TInt CheckCredential( const TDesC8& cr );

    /**

     * Stores cache to private file.

     */

    void StoreToFileL();

    /**

     * Reads cache data to iBuf.

     */ 

    TInt ReadFile();

    /**

     * Stores file name with path to iFileName.

     * Creates private path if needed.

     */

    TInt CreateFileNameAndPath();

    RFs iFs;

    TCacheBuffer iBuf;

    TFileName iFileName;

    MIkeDebug& iDebug;

};

#endif  // CREDENTIALCACHE_H